The invention relates to a device for displaying images comprising:                an image display panel comprising a first and a second array of electrodes serving an array of electroluminescent cells, where each cell is powered between an electrode of the first array and an electrode of the second array.        power supply means linked to said arrays of electrodes,        drive means for each of said cells of the panel, and        means for processing data of the images to be displayed so as to parameterize said drive means.        
The first array of electrodes generally corresponds to columns and the second array to rows: as power supply means use is generally made of a current or voltage generator; the drive means generally comprise column and row drivers which serve to link the power supply means to the arrays of electrodes.
In such panels, the distance separating the two arrays of electrodes is very small; at the level of each cell, this distance corresponds to the thickness of an electroluminescent organic layer which is commonly of the order of 0.1 μm; therefore, the electrical capacitance between the electrodes of the two arrays is significant and the intrinsic capacitance at the level of each cell is therefore high.
Each image to be displayed is divided into pixels, themselves subdivided into as many subpixels as primary colors; to each subpixel is allocated a luminous intensity datum for the image to be displayed; to display an image, each subpixel of the image is assigned to a cell of the panel.
In such a device, the drive means are adapted:                for successively connecting each electrode of the second array to one of the terminals of the power supply means; these steps of the method correspond to the scanning of the lines of the panel;        and, during the sequence of connection of an electrode of the second array, for simultaneously connecting electrodes of the first array to the other terminal of the power supply means.        
If the duration of the connection of each electrode of the first array or of activation of the column driver depends on the luminous intensity datum attributed to the cell powered via this column, the duration of power supply of a cell corresponds to the width of a voltage or current pulse, and the driving of the panel is then said to be carried out by pulse width modulation, or is of PWM type.
During the displaying of images, each time a cell of the panel is connected and powered, its intrinsic capacitor is charged; at the end of each sequence of connection of an electrode of the second array or of the scanning of a line, all the cells served by this electrode or this line are disconnected, and before passing to the next sequence of connection of another electrode of the second array or of the scanning of another line, all these intrinsic capacitors are discharged so that the luminous intensity of the cells served by this other electrode or other line is not disturbed by the intrinsic charges accumulated during the previous sequence relating to the previous line.
Accordingly, it is know practice to add an intermediate sequence of discharge, for example via shunting means as described in document U.S. Pat. No. 6,339,415—PIONEER; during this intermediate step of discharge, the intrinsic capacitors of the cells of the line that has just been scanned are discharged to earth.
The drawback of such a procedure of driving with intermediate discharge of each line is that the capacitive energy of the intrinsic capacitors is lost.
The document EP 1091340 describes a procedure for capacitive energy recovery which is limited: specifically, the energy originating from a first cell is recovered for the benefit of another cell only if the video signal to be displayed at this other cell is greater than the video signal displayed at the first cell; the drawback of this procedure is that, in the converse case where the video signal is less, the capacitive energy of the first cell is lost.